Towards a better knowledge of insulating polymers under stress

This contribution to a better understanding of insulating materials which a re evolving in the domain of electrical engineering, concerns two polymers: a low density polyethylene free of additives, and an amorphous and bi-axia lly oriented poly(ethylene-2,6 dicarboxylate). Through conductivity, dielec tric relaxation and luminescence measurements the importance is shown of th e role played by the structure of the material on its electrical properties . Also, the evolution of these properties under electrical stress or enviro nmental conditions, such as electrical discharges, are studied.